Dual Monitor issues with KVM

I wasn't sure what the appropriate category was for this post, so feel free to move this if I've placed improperly. I have 2 laptops and one separate monitor. I have an IOGEAR KVM to swap between the two with the separate monitor plugged into the KVM. This separate monitor completes a dual display setup for each of the two laptops. When I toggle between the two laptops, the separate monitor is correctly identified as the second monitor in each configuration. Here is my issue…when I toggle from laptop 1 (Dell XPS with Windows 7) to laptop 2 (IBM Lenovo T400 with XP Pro), laptop 1 recognizes that all of the windows on the second monitor should stay on the second monitor even though the second monitor is now being used for laptop 2. When I toggle back from laptop 2 to laptop 1, laptop 2 no longer recognizes that the second monitor and kicks all of the second monitor windows to the display of laptop 2. Obviously, laptop 2 believes it is a single monitor setup when the KVM is directed to laptop 1…but the curious thing is that I am using UltraMon on both systems to manage the dual display configuration and the options and settings are the same on both. Why would one system decide it is suddenly a single display setup when the KVM is pointed to the other laptop, but the other one not behave that way?? Is there perhaps an XP specific or Lenovo setting I need to check somewhere??

Graphics adapters are not designed to have monitors "hot-swapped" in and out so that may be part of the problem. If you change laptop positions on your KVM, that is, make the Dell laptop 2 and the Lenovo laptop 1, is it still the Lenovo that forgets the 2nd display or is it now the Dell? If now the Dell, then the KVM is the problem.

Graphics adapters are not designed to have monitors "hot-swapped" in and out so that may be part of the problem.

If you change laptop positions on your KVM, that is, make the Dell laptop 2 and the Lenovo laptop 1, is it still the Lenovo that forgets the 2nd display or is it now the Dell? If now the Dell, then the KVM is the problem.

I try what Digerati said first, I use KVM die hard and never ran into a problems with differant montiors or systems, out of 5 years using them only one problem was not syncing or as I would call it lock up, but I think that was due to a cheap KVM.


If you can try or know someone with a kvm to use that could be a way to trouble shoot also.

Jimbo1

Digerati and Jimbo1….I have not yet swapped what laptop goes on which port of the KVM since I got it working, but will give it a try when I get home from work tonight. Thanks for the suggestions. I just got the KVM this past Thursday and initially could not get the KVM to toggle. I tested every USB port on both laptops and swapped the laptops around to try them on each port before deciding that port 2 on the KVM was bad. I just went out last night and exchanged the KVM for a new one and hooked the new one up. Worked immediately except for the issue I posted about on this board. I'll let you know later if swapping them results in the Dell seeing the same issue or not.

Well, I have used several KVM switches and there are definitely good and not-so-good quality versions. And the quality can be (or not be) in the mechanical switch, electronics behind the switch, or the cable connections, or all of the above. Long cables can play a part too. The more connections and distance between the computer and monitor the greater the signal loss due to friction/resistance.

Digerati….I swapped which laptop was connected to what port on the KVM. The Dell (Win7) still properly manages the second monitor when I toggle to the other laptop. The IBM Lenovo also (unfortunately) functions the same even on the different KVM port….that is, when I toggle away from it the windows on the second screen jump back to the primary laptop display. This for the most part, to me anyway, eliminates the KVM as the culprit. I'm left thinking it is more an XP specific or an IBM Lenovo problem. Perhaps a setting that needs to be tweaked. I'm also more inclined to suspect it is related to the laptop itself and not XP as I think I'd be seeing/finding similar issues posted by others if it was an XP thing. I'd certainly be appreciative of any other suggestions anyone here could make with respect to this odd issue. Thanks everyone…these boards are a great medium for discussion and support.

I suspect it is a graphics hardware timing issue in the Lenovo and there is probably nothing you can do about it. You can look in the BIOS or graphics driver properties but don't hold your breath. As I noted before, graphics cards don't natually support hot-swapping monitors. That support may have something to do with KVM switches and maybe a better switch will hold the settings longer? I don't know. Just guessing now. If you fiture it out, let us know. Maybe you could borrow another notebook and see what it does.

my guess would be one wire is sending a connection signal from the laptop to the monitor and back, now when you use the kvm switch the connection signal disappears, one laptop ignores the loss of the connection signal or never checks for it after first detection, while the other laptop continuously checks that signal and when it disappears recognizes the fact that now only one display is connected so puts all open windows onto that one display. not sure if you can get a kvm switch that will always make that connection signal live so no matter what position it's in, any connected pc's/laptops will see it as a connected monitor or maybe if you can find a wiring diagram and jury rig the switch so that signal wire is always live with the 5v or whatever signal, then the laptop will still think there is a monitor connected even when it's switched to the other laptop and stop moving all the windows.

Is that a true "multimonitor" KVM? What is the make and model number?

Hi Digerati, The KVM I am using is an IOGEAR GCS632U.

I don't know where I was going with that multi-monitor KVM question. You are using the laptops monitors and swinging the exterior monitor. Sorry about that. I think it is just the way the Lenovo behaves. You could try a 3rd notebook to be sure.